Process for regulating setting time of hydraulic cement

ABSTRACT

The present invention is an improved one of U.S. Pat. No. 3,782,992 and relates to a process for regulating setting time of hydraulic cement which comprises clinker containing 5 - 60 percent by weight of 11CaO.7Al2O3.CaX2, more than 5 percent by weight of 3CaO. SiO2, anad further 2CaO.SiO2 solid solution and 4CaO.Al2O3.Fe2O3; anhydrite with or without hemihydrate; at least one selected from the group consisting of sugars, sodium hydrogen carbonate, water-soluble phosphates, carboxylic acids, silicofluroides, sodium silicates, ligninsulfonate, sulfuric esters of higher alcohol and alkylsulfonates, whereby the anhydrite is contained in an amount that Al2O3/SO3 weight ratio of Al2O3 in the clinker and SO3 in the anhydrite is 0.7 - 1.8 and hemihydrate is contained less than 5 percent by weight based on SO3.

AU 115 EX Feb. 4, 1975 1 PROCESS FOR REGULATING SETTING TIME OFHYDRAULIC CEMENT [75] Inventors: liiroshi Uchikawa, Funabashi;

Shunichiro Uchida, Chiba, both of Japan [73] Assignee: Onoda Cement Co.,Ltd., Onoda-shi,

Yamaguchi-ken, Japan [22] Filed: July 6, 1973 [21] Appl. No.: 377,112

Related U.S. Application Data [62] Division of Ser. No. 253,352, May15,1972.

OTHER PUBLICATIONS Taylor; W. H. W. H. Concrete Tech. and practice,

Amer. Elsevier Pub. Co., New York, 1965. pp. 184-185.

Primary Examiner-Delbert E. Gantz Assistant Examinerlames W. HellwegeAttorney, Agent, or Firm-Oblon, Fisher, Spivak. McClelland & Maier [57]ABSTRACT The present invention is an improved one of U.S. Pat.

No. 3,782,992 and relates to a process for regulating setting time ofhydraulic cement which comprises clin; lge r containing 5 60 percent byweight of 1 a 7Al O CaX more than 5 percent by weight 0 3Ca0.

W further 2CaO.SiO solid solution and 4CaO.Al O .Fe O anh drite with orwithout hemihyo drate at leasLonesselected from the group consisting ofsugarswjy droge n carbonate, water-soluble phosphates, carbggylicflagids, sTli cofluroides, sodium silicates,lignigsulfonatefsulfuri; estersof higher alcohol an d al ylsulfonates,whereby the anhydrite is contai rTd in an amount that Al O /SO weightratio of A1 0 in the clinker and S0 in the anhydrite is 0.7 1.8 andhemihydrate is contained less than 5 percent by weight based on S0 7Claims, 4 Drawing Figures PATENTED FEB "1175 Compressive Strength ofCemenfl lcm SHEET 10F 4 FIG. 1

PATENTED 4W5 3.864.141

SHEET 20F 4 FIG. 2

Difference between Initial and Flnal Semng T|me(m|n) Added Amount ofGulactoseh: IO"

, v E 40 g, 2 rt g 20 I G) (0 IO 0Y5 |.'o H5 2T0 Added Amount ofGc||ucfose (xl0"%) PATENTED FEB 75 SHEEI 3 OF 4 FIG.3

PATENTEUFEB, 41815 SHEET l UF 4 FIG.4

28duys A EQ ZEQEZm 3 538500 Added Amount of N0 SiF (based on F) retaide'PROCESS FOR REGULATING SETTING TIME OF HYDRAULIC CEMENT This is adivision, of application Ser. No. 253,352, filed May I5, 1972.

The present invention relates to a process for suitably regulatingsetting time of hydraulic cement which has high strength at the initialand later stages. The initial and later stages means less than 6 hrs andmore than 3 days respectively, in the present invention.

When the mixed raw materials comprising calcareous, silicious andaluminous material as well as a small amount of halide such as calciumfluoride, calcium chloride, etc., are sintered, the initialcrystallization region of filqium aluminate (3CaO.Al,O is extremelynarrowed and the clinke obtained will not contain calcium aluminate, andcontains llCaO. 7Al,O .CaX, (X represents a halogen atom) as a stablephase, and thus the clinker containing l lCaO.7Al O .CaX, as a stablephase. as well as 3CaO.SiO,, 2CaO.SiO,, 4Ca0.Al O Fe,O etc. is obtained.

llCaO.7Al,O,.CaX component has a high hydration activity and a greaterhardenability, so it is effective that hemihydrate (or h en ihydgategypsum) is FIG. 2 shows the relation between a difference be tween theinitial and the final setting time or the setting time of the cementmortar as used in FIG. I and theadded amount of galactose.

FIG. 3 shows theTe'fifion between the compressive strength of ce nt rtarc rising the clinker and Alp /S0 ratio of A1 0 in the clinker and SO, inanhydrite.

FIG. 4 shown the relation between the compressive strength of cementmortar comprising the clinker and the added amount of sodiumsilicofluoride (based on F).

Bauxite, quick lime, and copper slag as well as fluorite were ground,respectively, and mixed so as to obtain clinker having a composition asshown in Table I. The resulting mixture was shaped and sintered at l,320I,330C. The thus obtained clinker was ground to powder having Blainespecific surface area of 3,700 cm /g. The composition of the clinkeranalized by X ray diffraction analysis are shown in Table I.

Table I Chemical composition Mineral composition SiO, 17.7

CaO 62.3

Total MgO added to the clinker containing llCaO.7Al,O .CaX component forretarding the setting time thereof and also 'nsol e anh d 'te (orinsoluble anhydrite gypsum) is added to the clinker containingllCaO.7Al- O .CaX, for developing strength in the initial and the laterstages. However, as disclosed by US. Pat. No. 3,782,992, we have foundthat if at least one of sulfates, nitrates and clgorides of potassium,sgdhgm, magneslum, calcium, aluminium and ammonium (exceptingCaSo,.l/2l-l;O), is added to the clinker as ag bstitute of hemih drate,setting time of cement thus obtaiie'dis and the hardened ma'tieF hasexcellent strength. and that if the above-mentioned additive is added tothe clinker with anhydrite and hemihydrate, setting time of cement thusobtained is retarded and the cement have good workability and moreexcellent strength development property at the early and the laterstages than that of the former cement. The early stage means between 6hrs and 3 days in the present invention.

An object ofthe present invention is to provide a process for regulatingsetting time of hydraulic cement comprising llCa0.7Al,O .CaX by using anadditive other than the above-mentioned additives.

Another object of the present invention is to provide a process forpreparing cement which has good workability and high initial strengthand a hardened material thereof has high strength for a long period oftime.

We found that in addition to the above-mentione additive, sodiumhydrowatg, water-soluble phosphates, silicofluorides, sodium silicates,sugars, carboxylic acids, ligninsulfonates, sulfuric esters of higheralcohol or alkylsulfonates is effective.

The present invention can be more fully understood from the followingdetailed description when taken in conjunction with reference to theaccompanying drawings, in which:

Natural gypsum having a composition of Table 2 was used to produce thefollowing products.

Hemihydrate: The natural gypsum of Table 2 was kept at l60C for 3 hoursand was cooled and ground to powder having a Blaine specific surfacearea of 5,000 cm /g.

Insoluble anhydrite: The natural gypsum ofTable 2 was kept at 800C in anelectric furnace for I hour, and was cooled and ground to powder havinga Blaine specific surface area of 4,200 cm /g.

These gypsum products were used after the chemical form thereof wasidentified by thermal analysis such as diffrential thermal analysis orthermobalance analysis.

In order to determine the relation between the amount of galactose to beused and the setting time or the compressive strength after setting ofcement mortar, the setting time and the compressive strength of mortarwere determined with respect to cement in which galactose was mixedalone and in which anhydrite was mixed in combination with galactose inan amount that AhO /SO, ratio of A1 0 in the clinker and SO; inanhydrite is 1.2 by weight.

The initial and final setting time of mortar are determined inaccordance with the test method for setting of paste described in S R5201, using a sample of which the cement/standard sand (yielded inTOYOURA) ratio is l 2 by weight. and water/cement ratio is 0.55 byweight and the strength of mortar is determined in accordance with thetest method described in HS R 520i.

The results are shown in FIG. 1 and FIG. 2. In these figures, numerals land 2 show the cases which anhydrite is not added and is added,respectively.

It has been found from these results that when galac- 4 drate to percentmixture of anhydrite and sodium silicofluoride as compared FIG. 3 withFIG. 4.

Table 3 shows the relation between the setting time and the compressivestrength of mortar when amount of sodium silicofluoride.

It has been found also that the initial and later strength of mortarincrease with addition of hemihytose is used alone, the setting time ofmortar is retarded 5 percen by weight of anhydrite or a mixture of 13perand the compressive strength of mortar in the initial cent by weightof anhydrite and 2 percent by weight of stage increase with increaseofthe'am ount ofgalactose, hemihydrate are added to the clinker shown inTable Table 3 p Amount of addition Setting time Compressive strength ofmortal (kg/cm) 3 of mortal (min.) (linker Anhydrite Hemihydrate AdditiveInitial Final 3 hrs. 6 hrs. l day 3 days 7 days 28 days 35 "I3 2 I7 25I05 H2 1% 295 340 43s Cane sugar 85 I5 0.3 14 23 80 I24 I97 310 363 445Cane sugar 85 I3 2 0.3 28 I37 I48 256 288 375 513 Sodium dihydrogen 85I5 phosphate 0.3 19 24 I22 I35 2 I2 286 346 446 (based on P,O 85 I3 do.24 30 I33 I56 240 3I0 357 475 Adipic acid 85 I5 'UTI 14 I8 I I5 I27 240290 343 450 85 I3 2 do. 23 30 I02 I62 263 325 384 476 but when galactoseis added more than a fixed amount, I and the above-mentioned additivesare added to the the compressive strength in the initial stage islowered. thus obtained cement.

In contrast With the above-mentioned, It has been As has been observedin the above when found ihatwhe" anhydrite in fombmatlon drate is addedto the clinker, the initial and later galactosealli'lough g l muffledf"? strength of the thus obtained cement increase. ti i gg z i f lik gfz "p i The relation between the setting time or the comer zf g 1' ipressive strength, and amount of used additives was 0 an y q g ff 6588I3 studied with respect to clinkers containing 5 60 perf o a an z gfcent of l lCaO.7Al O .CaX and more than 5 percent as 3 w a of 3CaO.SiOand further 2cao.sio,, 4ca0.AI,o,, etc. than galactose, such as sodiumhydrogen carbonate,

. 35 and the results were similar as the results obtained bywater-soluble phosphates, carboxylic aclds. sIlIcofluothe abov membnedex eri ems rides, sodiu silicates, ligninsulphonates, higher alcol p mhol sulfur e st emylsulfonate is used, a similar re- The P t" mv'rnuonrekftes to a for l suh as the abovememioned is obtained Ing setting timeof hydraulic cement which comprises The relation between the compressivestrength f clinker containing 5 60 percent by weight of l lCaO.- mortarand the added amount of anhydrite was studied 40 f more than f by wlghtof 3Ca0" with respect to cement in which sodium fluosilicate is andfurther f p sohd 'solut'on 4Cao' added 1.2 percent by weight based on Fand anhydrite Aboa'Feioai anhydme wlthout hefmhydratei is added atvarious Alfi /S0 weight ratio of A1 0, in at least 9 Selected from thegroup Consisting of the clinker and so in anhydrite to the abovee Sodiumhydrogen carbonate, Water-soluble p smentioned clinker. These resultsare shown in FIG. 3. phalesi ("tho P P Fi py p p f i As has beenobserved in the above no.3, it is preferl p rg a P y 9 -i rt gg i ableto add insoluble anhydrite to the clinker in an afhpmlmlietc'hsllfcofluonmmesamount that the ratio f 0 in the clinker andmnsulfonates, sulfuric esters of higher alcohol and alin the anhydrite,that is, Alp /S0 ratio is between 0.7 kylsulfonates. whereby the a y e1s wmameq m an and 1'8, 50 amount that Al O /SO weIght ratio of M 0; Inthe It has been found also that when an additive other clinker t" a fthe anhydrite and than sodium silicofluoride is used, a similar resultas the hydrate comamed [e hall 5 ptrrcent y weight above-mentioned isobtained as shown by the addition based 3- f di ili fl id In the presentinvention, the above-mentioned addi- Th l i b tw th compressive strengthf 55 tives should be used preferably in an amount of 0.01 mortar and theadded amount of sodium silicofluoride Percent y Weight for fl sfl ch d i0' -7 was studied with respect to cement in which various p r en yWeigh! for disflcchafdie. 0 Percent amounts ofsodium silicofluoride areadded to the mixby weight for polysaccharide, 0.l 1.5 percent by ture of13 percent by weight of anhydrite and 2 percent weight for sodiumhydrogen carbonate; 0.1 2.0 perby weight of hemihydrate. These resultsare shown in cent by weight based on P 0 for water soluble phos- FI 4,phates (orthophosphates, pyrophosphates and tripoly- As had beenobserved in the above FIG. 4, the comphosphates); 0.1 5.0 percent byweight based on F for pressive strength of the mortar increase graduallywith silicofluorides (Mg-, Ca-, Na-salts), 0.1 5.0 percent increase ofthe added amount of sodium silicofluoride by weight for sodiumsilicates; 0.03 3.0 percent by and decreases gradually after addition ofa fixed weight for sulfuric acid esters of higher alcohol andalkylsulfonates; and 0.01 1.00 percent by weight for oxyacids, e.g.,tartaric acid etc. or dicarboxylic acids, e.g. adipic acid etc."

The added amount lower than one shown in the above is not effective forthe setting time and the compressive strength of mortar or concrete andthe added amount more than one shown in the above extremely retards thesetting time and lowers the strength at the later stage as well as atthe initial stage.

As has been explained above, existence of anhydrite in clinker isresponsible for the initial and later high strength development ofcement. Addition of anhydrite with hemihydrate in clinker is effectivefor increasing the initial and later strength. The added amount ofhemihydrate is preferable to be 0.1 5.0 percent by weight based on S0,for cement and the added amount of anhydrite is most preferable to be0.7 l.8 at A1 SO, weight ratio of the amount of Al O in the clinker andthe amount of SO; in the anhydrite and hemihy drate in the cement. WhenAl O /SO ratio is lower than 0.7, the hardened material of mortar orconcrete is cracked and broken down and when Al O /sO ratio is more than1.8, the compressive strength of mortar or concrete decreasesremarkably.

According to the present invention, the setting time of mortar which isprepared from the clinker comprising 5 60 percent by weight of llCaO.7Al,O;,. CaX more than 5 percent by weight of 3CaO.SiO,, 2CaO.-SiO,, 4CaO.Al O .Fe O etc. is not only regulated within a range of from7 to 40 minutes, but also the mortar or concrete provicl mtclworkability and the hardened material thereof develops excellentstrength at the initial and the later stages.

Example White clay, white bauxite, quicklime. copper slag and a smallamount of gypsum as well as calcium fluoride, calcium chloride weregrounded by a shaft ball mill. 85 cm in diameter and 100 cm in length,and were mixed by means of a large-sized mixer so as to obtain clinkerhaving a composition as shown in Table 4 and the resultant mixture wasshaped by a rotating roll, 60 cm in diameter. The shaped material issintered by a small-sized rotary kiln so that free lime in the obtainedclinker was lower than 0.5 percent by weight. These results are shown inTable 4.

The obtained clinker was mixed with gypsum listed in Table 5,calciumjigninsulfonat e, caicium'alkylsulfonate and sulfuric ester ofhigher alcohol, sodium hydrogen carbonate, sodium tripolyphosphate,magnesium silicofluoride, respectively, at the ratio listed by Table 6and each thus prepared cement was tested for the settingtime andcompressive strength of mortar in accordance with the test method S R5201. The results are summerized in Table 6. In Table 6, the settingtime and the compressive strength of mortar prepared from cement whichwas mixed along gypsum to the above clinker were listed to compare withthe above results.

Table 4 Kind of Chemical composition Free Mineral composition (72)clinker SiO, Al,O Fe,O CaO MgO SO Na,O K O Total lime C ,A .CaX, C.

A l5.9 l5.7 2.3 61.9 0.5 1.2 0.08 0.07 97.6 0.2 X= SI 27 B 17.8 l5.l 2.06l.5 0.4 l.0 0.03 0.05 97.9 0.! X2=CI 44 Note: Mineral composition wasdetermined by means of X-ray diffraction analysis.

Table 5 Kind of gypsum ig.loss SiO, A|,0,--Fe,0. CaO MgO SO: TotalHemihydrate 6.1 1.8 0.9 37.5 0.2 53.6 [00.1 Anhydrite L9 L0 40.0 0.357.2 100.4

Table 6 Setting time of Amount of addition(% by weight) mortar (min.)Compressive strength of mortar (kg/cm) Clink- Anhy- Hemi- AdditiveInitial Final 3 hrs. 6 hrs. l day 3 days 7 days 28 days er drite hydrateA 13 2 I6 24 I05 I24 217 249 333 450 85 (20.4) (30.2) (48.8) (50.3)(62.5) (88.4)

surfige a ct ye gent A comprising mainly l I8 I27 204 308 354 495 85 I5calcium li nin- (25.4) (29.8) (40.4) (65.4) (70.7) (89.9)

sulfonate .3

A Sodium hydrogen 108 I36 239 288 3l8 466 85 I5 carbonate 0.8 (24.4)(30.1) (49.5) (53.3) (68.2) (89.7) A Sodium tripoly- 1 I0 I26 250 289345 453 85 I5 phosphate 0.5 (25.3) (27.4) (55.6) (57.9) (72.4) (87.l) AMagnesium silicol36 I66 262 3l0 357 49l l2 2 fluoride 2.0 (based 25 84on F) (3L6) (36.5) (55.6) (60.0) (73.!) (90.6)

\Surface active agent A comprising mainly I30 I54 246 276 343 484 85 I5sulfuric ester 23 30 (30.5) (33.6) (52.3) (57.4) (7L5) (90.4)

of higher alcohol 0.3 B Magnesium silico- I25 I 224 275 324 478 84 14fluoride 2.0 26 34 (25.4) (30.4) (49.9) (56.8) (62.5) (82.6)

Surface active agent A comprising mainly 124 I 230 293 326 476 85 I5calcium alkyl- I5 25 (27.6) (34.2) (50.9) (59.6) (69.5) (88.1)

sulfonate 0.3"

Note:-

I) Values in parentheses show bending strength (kg/n13) 2) Mark: showsth n the compound is sowed in water kneaded together with cement What isclaimed is: l. A process for regulating the setting time of a hydrauliccement, which comprises the steps of:

admixing the retarders anhydrite and 0.01 1.0 weight percent of acarboxylic acid with a clinker consisting essentially of5 60 weightpercent of l l CaO.7Al:O .CaX whereiri X represents a halogen atom, andmore than 5 weight percent of 3 CaO.- SiO solid solution, 2 CaO.SiOsolid solution and 4 CaO.Al O;,.Fe,O wherein the anhydrite is present inan amount such that the weight ratio of M in the clinker to S0 in theanhydrite is 0.7 1.8. 2. A process claimed in claim 1, wherein thecement comprises anhydrite and hemihydrate.

3. A process claimed in claim 2, wherein the cement comprises less than5 perWy- Aws- 4. A process claimed in claim 1, wherein the cementcomprises 0.01 1.00 percent by weight of at least one 8 member selectedfrom oxyacids and dicarboxylic acids.

5. A hydraulic cement composition. consisting essentially of:

5 weight percent of I] CaO.7Al,O;,.CaX wherein X represents a halogenatom, more than 5 weight percent of 3 CaO.SiO, solid solution andfurther 2 CaO.SiO, solid solution and 4 CaO.Al- O .Fe,O anhydrite; and0.01 1.0 weight percent of a carboxylic acid, wherein the anhydrite iscontained in an amount such that the Al,O /SO, weight ratio of A1 0 inthe clinker and SO; in the anhydrite is 0.07 1.8.

6. A hydraulic cement composition as described in claim 5, wherein thecement composition comprises anhydrite and hemihydrate.

7. a hydraulic cement composition as described in claim 6, wherein thecement composition comprises hemihydrate less than 5 percent by weight.

2. A process claimed in claim 1, wherein the cement comprises anhydriteand hemihydrate.
 3. A process claimed in claim 2, wherein the cementcomprises less than 5 percent by weight of hemihydrate.
 4. A processclaimed in claim 1, wherein the cement comprises 0.01 - 1.00 percent byweight of at least one member selected from oxyacids and dicarboxylicacids.
 5. A hydraulic cement composition, consisting essentially of: 5 -60 weight percent of 11 CaO.7Al2O3.CaX2, wherein X represents a halogenatom, more than 5 weight percent of 3 CaO.SiO2 solid solution andfurther 2 CaO.SiO2 solid solution and 4 CaO.Al2O3.Fe2O3; anhydrite; and0.01 - 1.0 weight percent of a carboxylic acid, wherein the anhydrite iscontained in an amount such that the Al2O3/SO3 weight ratio of Al2O3 inthe clinker and SO3 in the anhydrite is 0.07 - 1.8.
 6. A hydrauliccement composition as described in claim 5, wherein the cementcomposition comprises anhydrite and hemihydrate.
 7. a hydraulic cementcomposition as described in claim 6, wherein the cement compositioncomprises hemihydrate less than 5 percent by weight.